keepalived vrrp 主从切换配置如下：（以下是两组主从为例，单组也可以）
注意事项：
1.同一组主从vrrp_instance， virtual_router_id 必须相同

2. MASTER priority值大于BACKUP priority

只有在keepalived 服务stop时，virtual_ipaddress才会漂移或者说主从才会切换

MASTER

vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 51
    priority 101
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.10.10
    }
track_script {                    
   chk_http_port                  
}
}

vrrp_instance VI_2 {
    state BACKUP
    interface eth0
    virtual_router_id 31
    priority 61
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.10.20
    }
track_script {
   chk_http_port
}
}

BACKUP

    state BACKUP
    interface eth0
    virtual_router_id 51
    priority 99
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.10.10
    }
track_script {
   chk_http_port
}
}

vrrp_instance VI_2 {
    state MASTER
    interface eth0
    virtual_router_id 31
    priority 69
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.10.20
    }
track_script {
   chk_http_port
}
}